Across the River Boyne from Trim Castle are the ruins of the 12th-century Augustinian St Mary's Abbey, rebuilt after a fire in 1368 and once home to a wooden statue of Our Lady of Trim, revered by the faithful for its supposedly miraculous powers.
In 1415 part of the abbey was converted into a manor house by Sir John Talbot, then viceroy of Ireland; it came to be known as Talbot Castle.
On the northern wall of the castle you can see the Talbot coat of arms. Talbot went to war in France where, in 1429, he was defeated at Orleans by Joan of Arc. He was taken prisoner, released and went on fighting the French until 1453. He became known as 'the scourge of France' and even got a mention in Shakespeare's Henry VI: 'Is this the Talbot so much feared abroad/That with his name the mothers still their babes?'
In 1649 Cromwell's soldiers invaded Trim, set fire to the revered statue and destroyed the remaining parts of the abbey. In the early 18th century, Talbot Castle was owned by Esther 'Stella' Johnson, the mistress of Jonathan Swift. He later bought the property from her and lived there for a year. Swift was rector of Laracor, 3km southeast of Trim, from around 1700 until his death in 1745. From 1713 he was also, more significantly, the Dean of St Patrick's Cathedral in Dublin.
Just northwest of the abbey building is the 40m Yellow Steeple, once the bell tower of the abbey, dating from 1368 but damaged by Cromwell's soldiers. It takes its name from the colour of the stonework at dusk.
East of the abbey ruins is part of the 14th-century town wall, including the Sheep Gate, the lone survivor of the town's original five gates. It used to be closed daily between 9pm and 4am, and a toll was charged for sheep entering to be sold at market.